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Diffstat (limited to 'fs/nfs/fscache.h')
| -rw-r--r-- | fs/nfs/fscache.h | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/fs/nfs/fscache.h b/fs/nfs/fscache.h new file mode 100644 index 000000000..2a37af880 --- /dev/null +++ b/fs/nfs/fscache.h @@ -0,0 +1,149 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* NFS filesystem cache interface definitions + * + * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#ifndef _NFS_FSCACHE_H +#define _NFS_FSCACHE_H + +#include <linux/swap.h> +#include <linux/nfs_fs.h> +#include <linux/nfs_mount.h> +#include <linux/nfs4_mount.h> +#include <linux/fscache.h> +#include <linux/iversion.h> + +#ifdef CONFIG_NFS_FSCACHE + +/* + * Definition of the auxiliary data attached to NFS inode storage objects + * within the cache. + * + * The contents of this struct are recorded in the on-disk local cache in the + * auxiliary data attached to the data storage object backing an inode. This + * permits coherency to be managed when a new inode binds to an already extant + * cache object. + */ +struct nfs_fscache_inode_auxdata { + s64 mtime_sec; + s64 mtime_nsec; + s64 ctime_sec; + s64 ctime_nsec; + u64 change_attr; +}; + +/* + * fscache.c + */ +extern int nfs_fscache_get_super_cookie(struct super_block *, const char *, int); +extern void nfs_fscache_release_super_cookie(struct super_block *); + +extern void nfs_fscache_init_inode(struct inode *); +extern void nfs_fscache_clear_inode(struct inode *); +extern void nfs_fscache_open_file(struct inode *, struct file *); +extern void nfs_fscache_release_file(struct inode *, struct file *); + +extern int __nfs_fscache_read_page(struct inode *, struct page *); +extern void __nfs_fscache_write_page(struct inode *, struct page *); + +static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp) +{ + if (folio_test_fscache(folio)) { + if (current_is_kswapd() || !(gfp & __GFP_FS)) + return false; + folio_wait_fscache(folio); + fscache_note_page_release(nfs_i_fscache(folio->mapping->host)); + nfs_inc_fscache_stats(folio->mapping->host, + NFSIOS_FSCACHE_PAGES_UNCACHED); + } + return true; +} + +/* + * Retrieve a page from an inode data storage object. + */ +static inline int nfs_fscache_read_page(struct inode *inode, struct page *page) +{ + if (nfs_i_fscache(inode)) + return __nfs_fscache_read_page(inode, page); + return -ENOBUFS; +} + +/* + * Store a page newly fetched from the server in an inode data storage object + * in the cache. + */ +static inline void nfs_fscache_write_page(struct inode *inode, + struct page *page) +{ + if (nfs_i_fscache(inode)) + __nfs_fscache_write_page(inode, page); +} + +static inline void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata, + struct inode *inode) +{ + memset(auxdata, 0, sizeof(*auxdata)); + auxdata->mtime_sec = inode->i_mtime.tv_sec; + auxdata->mtime_nsec = inode->i_mtime.tv_nsec; + auxdata->ctime_sec = inode->i_ctime.tv_sec; + auxdata->ctime_nsec = inode->i_ctime.tv_nsec; + + if (NFS_SERVER(inode)->nfs_client->rpc_ops->version == 4) + auxdata->change_attr = inode_peek_iversion_raw(inode); +} + +/* + * Invalidate the contents of fscache for this inode. This will not sleep. + */ +static inline void nfs_fscache_invalidate(struct inode *inode, int flags) +{ + struct nfs_fscache_inode_auxdata auxdata; + struct nfs_inode *nfsi = NFS_I(inode); + + if (nfsi->fscache) { + nfs_fscache_update_auxdata(&auxdata, inode); + fscache_invalidate(nfsi->fscache, &auxdata, + i_size_read(inode), flags); + } +} + +/* + * indicate the client caching state as readable text + */ +static inline const char *nfs_server_fscache_state(struct nfs_server *server) +{ + if (server->fscache) + return "yes"; + return "no "; +} + +#else /* CONFIG_NFS_FSCACHE */ +static inline void nfs_fscache_release_super_cookie(struct super_block *sb) {} + +static inline void nfs_fscache_init_inode(struct inode *inode) {} +static inline void nfs_fscache_clear_inode(struct inode *inode) {} +static inline void nfs_fscache_open_file(struct inode *inode, + struct file *filp) {} +static inline void nfs_fscache_release_file(struct inode *inode, struct file *file) {} + +static inline bool nfs_fscache_release_folio(struct folio *folio, gfp_t gfp) +{ + return true; /* may release folio */ +} +static inline int nfs_fscache_read_page(struct inode *inode, struct page *page) +{ + return -ENOBUFS; +} +static inline void nfs_fscache_write_page(struct inode *inode, struct page *page) {} +static inline void nfs_fscache_invalidate(struct inode *inode, int flags) {} + +static inline const char *nfs_server_fscache_state(struct nfs_server *server) +{ + return "no "; +} + +#endif /* CONFIG_NFS_FSCACHE */ +#endif /* _NFS_FSCACHE_H */ |